Multilayered pocketed bedding or seating product

ABSTRACT

A multilayered bedding or seating product comprising a spring core made up of an upper layer and a lower layer of pocketed coil springs. Each layer comprises a plurality of parallel strings of springs joined to each other. Each of the strings of springs comprises a row of interconnected pocketed coil springs. The strings of springs of the upper and lower layers may be secured to at least one scrim sheet therebetween.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to provisional patentapplication Ser. No. 60/401,476 filed Aug. 6, 2002 entitled“Multi-Layered Pocketed Bedding or Seating Product” which is fullyincorporated by reference herein.

FIELD OF THE INVENTION

[0002] This invention relates to spring assemblies for mattresses,cushions and other bedding or seating products.

BACKGROUND OF THE INVENTION

[0003] Bedding and/or seating products are commonly made from strings ofindividually pocketed springs. Such strings of springs are combined in aparallel fashion to create a spring assembly. In such products, each ofthe coil springs of the string is generally contained within anindividual pocket of fabric which extends from the top to the bottom ofthe spring. Typically, each of the springs within the string hasidentical features or characteristics. Consequently, bedding or seatingproducts made from identical strings of pocketed springs have uniformcharacteristics throughout the bedding or seating product.

[0004] Published PCT patent application Ser. No. WO 99/35081 discloses amattress having two layers of pocketed springs. Each of the springs ineach layer is individually pocketed, and the springs of the upper layerare directly above the corresponding springs of the lower layer. A pairof such corresponding springs, one above the other, are enclosed in anexternal cover and separated from one another by a generally horizontalpartition wall of the fabric which defines two pockets containing boththe upper and lower springs. The springs of the upper layer are “softer”than the springs of the lower layer. Thus, this mattress is able toprovide a soft upper layer and a harder or more firm lower supportinglayer. According to the disclosure of this PCT application, usingsprings having different characteristics in the different layers of themattress, differing degrees of firmness may be imparted to the mattress.

[0005] According to the disclosure of the above-identified PCTapplication, each row of pocketed springs is made up of pair of springs,one above the other, with one sheet of fabric folded or configured in aunique way such that each of the springs is individually pocketed withinthat single sheet. The effort and/or machinery required to individuallypocket each spring in this manner requires very special machinery whichincreases the cost of manufacturing the mattress, and also the timerequired to manufacture it. Additionally, the upper spring may movesideways relative to the lower spring, causing the springs to move outof alignment with one another and create a bump, indentation or unevenspot in the mattress. Another possibility with such a mattress is thatthe spring of the upper layer may rotate relative to the spring of thelower layer, reducing the ability of the mattress to function asdesired.

[0006] Therefore, it has been one objective of the present invention toprovide a multilayered bedding or seating product made of individuallypocketed springs wherein each coil spring is surrounded or pocketedwithin its own sheet of fabric but which may be relatively inexpensivelymanufactured on currently existing machinery and which is not subject tothe misalignment problem described hereinabove.

[0007] Another objective of the present invention has been to provide abedding or seating product made from a plurality of layers of similarlypocketed strings of pocketed springs joined together so as to locate onespring of each layer in axial alignment with a spring of the other layeror layers.

[0008] Still another objective of the present invention has been toprovide a pocketed bedding or seating product which may be custommanufactured for a particular application.

SUMMARY OF THE INVENTION

[0009] The invention of this application which accomplishes theseobjectives comprises a pocketed spring bedding or seating product. Thebedding or seating product comprises a multilayered spring core and anupholstered covering surrounding the spring core. Each layer of thespring core comprises a separate spring core assembly made from aplurality of parallel strings of pocketed springs joined together.

[0010] The spring core product made in accordance with this inventionhas an upper layer and a lower layer, each of the layers comprising aplurality of adhered or otherwise interconnected parallel strings ofsprings, each of the strings of springs comprising a row ofinterconnected, parallel coil springs. Each of the coil springs withineach string of springs is surrounded and encased in its own fabricpocket. In contrast to the spring core described in the above-identifiedPCT application, the fabric used to pocket the springs of the upperlayer in the practice of this invention is separate from the sheet offabric used to pocket the springs of the lower layer. Each row ofsprings is formed into a string of pocketed springs formed from onesheet of fabric, as is conventional.

[0011] In one embodiment of the present invention, the characteristicsof the springs of the upper layer are identical to the characteristicsof the springs of the lower layer. However, the coil springs of theupper strings of springs may be different; i.e., they may have differentcharacteristics than the coil springs of the lower strings of springs.However, it is envisioned that coil springs utilized in the practice ofthis invention may in at least one embodiment be conventional coilsprings having the same physical properties or characteristics, i.e.pitch, coil diameter, wire thickness (gauge), heat treatment, etc., fromtop to bottom.

[0012] In alternative embodiments of this invention the coil springs ofeach string of springs may have at least two distinctly differentportions in order to posturize the product into regions of differingfirmnesses. In these embodiments, each portion of a string of springshas different physical characteristics than at least one other portionof the string of springs.

[0013] Thus the bedding or seating product is multilayered, each layercomprising a plurality of pocketed springs, each of the pocketscontaining a coil spring.

[0014] The bedding or seating product typically has a longitudinaldimension and a transverse dimension, the longitudinal dimension beinggreater than the transverse dimension. However, the longitudinaldimension and transverse dimension may be identical in a square beddingor seating product. In the invention of the present application, thestrings of springs may extend longitudinally or transversely, dependingupon the desired effect.

[0015] Adjacent strings of springs of the bedding or seating product arepreferably glued together but may be otherwise secured to each other. Atleast one border wire may extend around the perimeter of the bedding orseating product and is secured to selected outermost pocketed coilsprings. Preferably, a first or lower border is secured to the lower endturns of the coil springs of the outermost springs of the lower layerand a second or upper border wire is secured to the upper end turns ofthe coil springs of the outermost springs of the upper layer. The borderwires provide stability to the completed assembly.

[0016] In one embodiment of the present invention, the strings ofsprings of the upper spring core assembly are adhered or otherwisejoined together. The strings of springs of the lower spring coreassembly, instead of being adhered or otherwise joined together, areglued, fastened or otherwise secured to upper and lower scrim sheets.The upper scrim sheet is secured to the tops of the strings of springsof the lower layer and the lower scrim sheet is secured to the bottomsof the strings of springs of the lower layer. The upper spring coreassembly, once assembled, is secured to the upper scrim sheet by gluing,ultrasonic welding or any other suitable method. In this manner, theupper and lower spring core assemblies are joined to a common scrimsheet or multiple scrim sheets located therebetween.

[0017] These and other objects and advantages of the present inventionwill be more readily apparent from the following detailed description ofthe drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a perspective view of a bedding product made inaccordance with the invention of this application comprising a pluralityof longitudinally extending strings of springs surrounded by a pair ofgenerally rectangular border wires.

[0019]FIG. 2 is a side elevational view, partially broken away, takenalong the view line 2-2 of FIG. 1 but with the border wires removed.

[0020]FIG. 3 is a side elevational view, partially broken away, takenalong the view line 3-3 of FIG. 1, again with the border wires removed.

[0021]FIG. 4 is a block diagram illustrating the process formanufacturing the bedding product illustrated in FIG. 1.

[0022]FIG. 5 is a perspective view of an alternative embodiment of thepresent invention comprising a plurality of longitudinally extendingstrings of springs surrounded by a pair of generally rectangular borderwires.

[0023]FIG. 6 is a side elevational view, partially broken away, takenalong the view line 6-6 of FIG. 5 but with the border wires removed.

DETAILED DESCRIPTION OF THE DRAWINGS

[0024] Referring to the drawings, and particularly to FIG. 1, there isillustrated a bedding or seating product 10 comprising a spring core 12,padding 14 and an upholstered covering 16 surrounding the padding 14 andspring core 12. The spring core 12 has an upper layer 18 and a lowerlayer 19, each layer 18, 19 comprising a separate spring core assembly20, 22, respectively, The upper spring core assembly 20 comprises aplurality of strings of springs 24 joined together. Likewise the lowerspring core assembly 22 comprises a plurality of strings of springs 26joined together.

[0025] As illustrated in FIG. 2, each of the upper strings of springs 24has a longitudinal dimension or length 28 and a height 30. Each upperstring of springs 24 comprises a row of interconnected fabric pockets 32formed from one sheet of fabric, each pocket 32 containing an upper coilspring 34. The combination of the upper coil spring 34 and the fabricpocket 32 is considered a pocketed coil spring 35. As is known in theart, each string of springs 24 comprises a piece of fabric folded overon itself encapsulating a plurality of parallel coil springs 34.Opposite sides or plies of the fabric are welded, glued, sewn orotherwise secured together at spaced intervals to create a pair ofoutermost vertical seams 36 and internal seams 40. Together with a topseam 38, the vertical seams 36, 40 form spring containing pockets, eachone of which contains at least one coil spring 34. Although the seams36, 38 and 40 are each illustrated as being a plurality of spaced,linear welded segments, these seams may as well comprise continuouslines or a series of dots of glue or sewn continuous seams as wellwithout departing from the spirit of this application.

[0026] Similarly, each of the lower strings of springs 26 has alongitudinal dimension or length 28 and a height 42. Each lower stringof springs 26 comprises a row of interconnected fabric pockets 44, eachcontaining a lower coil spring 46. Although the lengths of the upper andlower strings of springs 22, 24 are illustrated as being identical, theymay vary from each other. As illustrated, the height 30 of the upperstrings of springs 22 is greater than the height 32 of the lower stringsof spring 24, due primarily to the difference in the heights of the coilsprings 34, 46. However, the heights of the coil springs 34, 46 may beidentical, the lower coil springs 46 being further compressed than theupper coil springs 34 due primarily to the size of the pockets in whichthey are respectively located. Alternatively, the upper and lower coilsprings may have different characteristics such as pitch, heattreatment, coil diameter, etc. In addition, springs other than coilsprings may be incorporated into the present invention.

[0027] Referring to FIG. 2, each of the upper and lower coil springs 34,46 has an upper end turn 50, a lower end turn 52 and a plurality ofcentral convolutions 54 therebetween. In one embodiment, each of theupper coil springs 34 has the same physical properties as those of thelower coil springs 46. In another embodiment of the present invention,each of the upper coil springs 34 has different physical characteristicssuch as different thicknesses, coil pitches, coil diameters, heattreatments than those of the lower coil springs 46. Preferably, theupper coil springs 34 are “softer” or less firm than the lower coilsprings 46, to give the product an initial soft feel and more cushioningability.

[0028] Referring to FIG. 1, the bedding or seating product 10 has alongitudinal dimension L and a transverse dimension W, the longitudinaldimension L being greater than the transverse dimension W. Asillustrated in FIG. 1, the strings of springs 24, 26 may extendlongitudinally (parallel the longitudinal dimension L). Alternatively,the strings of springs 24, 26 may extend transversely (parallel thetransverse dimension W).

[0029] As illustrated in FIG. 1, a least one border wire may extendaround the perimeter of the spring core 12. FIG. 1 illustrates a lowerborder wire 80 secured to the lower end turns of the outermost lowercoil springs 46 of the lower layer 26 of the spring core 12. FIG. 1 alsoillustrates an upper border wire 82 surrounding the spring core 12.

[0030] With reference now to FIG. 4, there is illustrated the process bywhich the spring product illustrated in FIG. 1 is manufactured.Basically, that process comprises separately manufacturing the upperspring assembly 20 and the lower spring assembly 22 and then after thosetwo assemblies are completed, placing the upper assembly atop the lowerassembly and gluing or otherwise permanently securing the two assembliestogether.

[0031] In order to manufacture the upper spring assembly 20, the springs34 of the upper spring assembly 20 are serially formed in a conventionalspring-forming machine, after which those springs are serially formedinto a continuous string of pocketed springs as illustrated, forexample, in the Thompson U.S. Pat. No. 3,668,816 or the Stumpf U.S. Pat.Nos. 4,439,977 and 4,986,518. After formation of that continuous stringof pocketed springs, individual strings of springs are then cut with therequisite number of pocketed springs in the string. Those individualstrings are then assembled and glued or otherwise secured together toform the upper spring assembly as, for example, illustrated anddescribed in the Suenens et al. U.S. Pat. No. 5,126,604. The disclosureof these patents are hereby incorporated by reference for purposes ofcompleting the disclosure of this application.

[0032] The same process described hereinabove for forming the upperspring assembly 20 is followed for manufacturing the lower springassembly 22; that is, the springs of the lower spring assembly areformed, placed in a continuous string of pocketed springs, thatcontinuous string is then cut into individual strings of springs, whichare then assembled and glued or otherwise secured together to form thelower spring assembly 22.

[0033] After formation of those two spring assemblies, the upper springassembly 20 is then placed atop the lower spring assembly 22 and the twoassemblies permanently secured together as, for example, by gluing thebottom of the upper spring assembly 20 to the top surface of the lowerspring assembly 22. Thereafter, the complete spring product may becompleted by placement of border rods 80 and 82 around the periphery ofthe assembly and attachment of those border rods to the spring assemblyas, for example, by utilizing hog rings (not shown) wrapped around theborder rod and the outermost ones of the pocketed springs of the upperspring assembly to connect the upper border rod to the product and byutilizing hog rings wrapped around the lower border rod and the bottomturn of the edgemost springs of the lower spring assembly.

[0034] The border rods may be omitted from the spring product since thecomplete assembly is permanently secured as a consequence of the stringsof pocketed springs being glued or otherwise secured together in eachassembly and the two assemblies being secured together. In theillustrated preferred embodiment of the invention, the coil springs ofthe upper spring assembly are axially aligned with and of the samediameter coil springs of the lower spring assembly. Consequently, all ofthe coil springs in the lower spring assembly are axially aligned withthe coil springs of the upper spring assembly in this illustratedpreferred embodiment. Of course, that colinear alignment of the springsis not always necessary but is preferred in most applications of thisinvention in order to create a product which has a softer initial feelupon compression of the product.

[0035]FIGS. 5 and 6 illustrate an alternative embodiment of the presentinvention. For the sake of simplicity, like parts will be designed withlike numerals but with an “a” designation. The embodiment illustrated inFIGS. 5 and 6 comprises a bedding product 10 a comprising a spring core12 a, padding 14 a and an upholstered covering 16 a surrounding thepadding 14 a and spring core 12 a. The spring core 12 a has an upperlayer 18 a and a lower layer 19 a. The upper layer 18 a comprises anupper spring core assembly 20 a comprising a plurality of upper stringsof springs 24 a joined together. Similarly, the lower layer 19 acomprises an lower spring core assembly 22 a comprising a plurality oflower strings of springs 26 a.

[0036] Each of the upper strings of springs 24 a is joined to at leastone other upper strings of springs 24 a along the sides thereof, such astaught in U.S. Pat. No. 6,176,960, which is fully incorporated byreference herein. Other means of attaching the upper strings of springs24 a to each other may be used without departing from the spirit of thisinvention. The group of upper strings of springs 24 a joined togetherform the upper spring assembly 20 a.

[0037] Each of the lower strings of springs 26 a is not generally joineddirectly to adjacent strings of springs 26 a, but instead is joined toan upper scrim sheet 86 and a lower scrim sheet 88 by adhesive and/orany other fastening method. As best illustrated in FIG. 6, the upperscrim sheet 86 is glued or otherwise secured to the upper surfaces 90 ofeach of the lower strings of springs 26 a. Similarly, the lower scrimsheet 88 is glued or otherwise secured to the lower surfaces 92 of eachof the lower strings of springs 26 a. The lower strings of springs 26 awith the upper and lower scrim sheets 86, 88 secured together isconsidered the lower spring core assembly 22 a for purposes of thisapplication.

[0038] Once the lower spring core assembly 22 a is constructed, theupper spring core assembly 20 a is placed on top of the upper scrimsheet 86 and secured thereto with adhesive and/or any other fasteningmethod. Thereafter, the complete spring product 12 a may be completed byplacement of border rods 80 a and 82 a around the periphery of theassembly and attachment of those border rods to the spring assembly as,for example, by utilizing hog rings (not shown) wrapped around theborder rod and the outermost ones of the pocketed springs of the upperspring assembly to connect the upper border rod to the product and byutilizing hog rings wrapped around the lower border rod and the bottomturn of the edgemost springs of the lower spring assembly.

[0039] The upper and lower scrim sheets 86, 88 are preferably made of anonwoven fabric material but may be made of any flexible sheet material.In addition, several scrim sheets may be joined together before beingsecured to the upper and lower strings of springs 24 a, 26 a.

[0040] In this alternative embodiment illustrated in FIGS. 5 and 6 ofthe present invention, as with the embodiment illustrated in FIGS. 1-3and described above, either or both of the upper and lower spring coreassemblies may be posturized to provide multiple regions of differingfirmness. Such posturization may be achieved numerous ways, such as forexample, changing the characteristics of springs in the differentregions or changing the amount of compression of the pocketed springswithin different regions.

[0041] Although I have described several preferred embodiments of ourinvention, I do not intend to be limited except by the scope of thefollowing claims.

I claim:
 1. A bedding or seating product comprising: a spring corehaving an upper layer and a lower layer, each of said layers comprisinga separate spring core assembly comprising a plurality of parallelstrings of springs, each of said strings of springs being secured to atleast one adjacent string of springs and comprising a row ofinterconnected pocketed coil springs, said layers being joined together,one on top of the other, the springs of each layer being located inaxial alignment with the springs of the other layer, and an upholsteredcovering surrounding said spring core.
 2. A bedding or seating productcomprising: a spring core having an upper layer and a lower layer, eachof said layers comprising a separate spring core assembly comprising aplurality of parallel strings of springs, each of said strings ofsprings being secured to at least one adjacent string of springs andcomprising a row of interconnected pocketed coil springs, said layersbeing joined together, one on top of the other, the springs of eachlayer being located in axial alignment with the springs of the otherlayer.
 3. The bedding or seating product of claim 2 wherein each of saidstrings of springs made with one sheet of fabric.
 4. The bedding orseating product of claim 2 wherein said product has a longitudinaldimension and a transverse dimension, said longitudinal dimension beinggreater than said transverse dimension, said strings of springsextending longitudinally.
 5. The bedding or seating product of claim 2wherein said product has a longitudinal dimension and a transversedimension, said longitudinal dimension being greater than saidtransverse dimension, said strings of springs extending transversely. 6.The bedding or seating product of claim 2 further comprising at leastone border wire secured to select outermost pocketed coil springs. 7.The bedding or seating product of claim 2 wherein said upper layer isadhesively secured to said lower layer.
 8. The product of claim 2wherein said coil springs of said upper layer have differentcharacteristics than the characteristics of the coil springs of thelower layer.
 9. The product of claim 2 wherein the coil springs of saidupper layer are less firm than the coil springs of the lower layer. 10.A method of manufacturing a spring product which comprises: forming afirst plurality of coil springs, pocketing that first plurality of coilsprings in a first continuous string of spring-containing fabricpockets, cutting that first continuous string of spring-containingfabric pockets into a first series of multiple strings ofspring-containing fabric pockets, assembling and permanently securingtogether the first series of strings of spring-containing fabric pocketsto create a first spring assembly, forming a second plurality of coilsprings, pocketing that second plurality of coil springs in a secondcontinuous string of spring-containing fabric pockets, cutting thesecond continuous string of spring-containing fabric pockets into asecond series of multiple strings of spring-containing fabric pockets,assembling and permanently securing together the second series ofspring-containing fabric pockets to create a second spring assembly,placing the first spring assembly atop the second spring assembly andpermanently securing these two assemblies together to create a springproduct.
 11. The method of claim 10 wherein the first series of stringsof pocketed springs are permanently secured together by gluing and thesecond series of pocketed springs are secured together by gluing. 12.The method of claim 10 wherein the first spring assembly is permanentlysecured atop the second spring assembly by gluing.
 13. The method ofclaim 10 wherein the first spring assembly is placed atop the secondspring assembly with the axes of the springs of the first springassembly in colinear alignment with the axes of the springs of thesecond spring assembly.
 14. A bedding or seating product comprising: aspring core having an upper layer and a lower layer, each of said layerscomprising a separate spring core assembly comprising a plurality ofparallel strings of springs, each of said string of springs comprising arow of interconnected pocketed coil springs, said strings of springs ofsaid upper layer being secured to at least one adjacent string ofsprings, said strings of springs of said lower and upper layers beingsecured to at least one scrim sheet located between said layers suchthat said spring core assemblies are joined together, one on top of theother, and an upholstered covering surrounding said spring core.
 15. Abedding or seating product comprising: a spring core having an upperlayer and a lower layer, each of said layers comprising a separatespring core assembly comprising a plurality of parallel strings ofsprings, each of said string of springs comprising a row ofinterconnected pocketed coil springs, each of said strings of springs ofsaid upper layer being secured to at least one adjacent string ofsprings, said strings of springs of said lower and upper layers beingsecured to at least one scrim sheet located between said layers suchthat said spring core assemblies are joined together, one on top of theother.
 16. A bedding or seating product comprising: a spring core havingan upper layer and a lower layer, said upper layer of said spring corecomprising an upper spring core assembly comprising a plurality ofparallel strings of springs, each of said string of springs comprising arow of interconnected pocketed coil springs, each of said strings ofsprings of said upper layer being secured to at least one adjacentstring of springs in said upper layer, said lower layer of said springcore comprising an lower spring core assembly comprising plurality ofparallel strings of springs, each of said string of springs comprising arow of interconnected pocketed coil springs, each of said strings ofsprings of said lower layer being secured to upper and lower scrimsheets, said upper scrim sheet being located between said layers andsaid lower scrim sheet being located below said lower layer, saidstrings of springs of said upper and lower layers being secured to saidupper scrim sheet such that said spring core assemblies are joinedtogether, one on top of the other, and an upholstered coveringsurrounding said spring core.
 17. A bedding or seating productcomprising: a spring core having an upper layer and a lower layer, saidupper layer of said spring core comprising an upper spring core assemblycomprising a plurality of parallel strings of springs, each of saidstring of springs comprising a row of interconnected pocketed coilsprings, each of said strings of springs of said upper layer beingsecured to at least one adjacent string of springs in said upper layer,said lower layer of said spring core comprising an lower spring coreassembly comprising plurality of parallel strings of springs, each ofsaid string of springs comprising a row of interconnected pocketed coilsprings, each of said strings of springs of said lower layer beingsecured to upper and lower scrim sheets, said upper scrim sheet beinglocated between said layers and said lower scrim sheet being locatedbelow said lower layer, said strings of springs of said upper and lowerlayers being secured to said upper scrim sheet such that said springcore assemblies are joined together, one on top of the other.
 18. Amethod of manufacturing a spring product which comprises: forming aplurality of upper strings of springs, joining said upper strings ofsprings into an upper spring core assembly, forming a plurality of lowerstrings of springs, joining said lower strings of springs to at leastone scrim sheet, and placing the upper spring core assembly atop thelower spring core assembly and permanently securing these two assembliestogether to create a spring product.